Traffic Engineering (TE) is a technology that is concerned with performance optimization of operational networks. In general, Traffic Engineering includes a set of applications mechanisms, tools, and scientific principles that allow for measuring, modeling, characterizing and control of user data traffic in order to achieve specific performance objectives.
A circuit switched network usually includes multiple switch nodes (also referred to as “nodes”) which are arranged in a topology referred to in the art as a “mesh network”. Within the mesh network, user traffic can be transported between any two locations using predefined connections specifying particular links and/or switch nodes for conveying the user traffic.
The switch nodes in the mesh network are each provided with a control module. The control modules of the switch nodes function together to aid in the control and management of the circuit switched networks. The control modules can run a variety of protocols for conducting the control and management of the circuit switched networks. One prominent protocol is referred to in the art as “Generalized Multiprotocol Label Switching (GMPLS)”.
Generalized Multiprotocol Label Switching (GMPLS) is a type of protocol which extends multiprotocol label switching to encompass network schemes based upon time-division multiplexing (e.g. SONET/SDH, PDH, G.709), wavelength multiplexing, and spatial switching (e.g. incoming port or fiber to outgoing port or fiber). Multiplexing, such as time-division multiplexing is when two or more signals or bit streams are transferred over a common channel.
Generalized Multiprotocol Label Switching includes multiple types of label switched paths including protection and recovery mechanisms which specifies predefined (1) working connections within a mesh network having multiple nodes and communication links for transmitting data between a headend node and a tailend node; and (2) protecting connections specifying a different group of nodes and/or communication links for transmitting data between the headend node to the tailend node in the event that one or more of the working connections fail. Working connections may also be referred to as working paths. Protecting connections may also be referred to as recovery paths and/or protecting paths and/or protection paths. A first node of a path may be referred to as a headend node or a source node. A last node of a path may be referred to as a tailend node or end node or destination node. The headend node or tailend node initially selects to receive data over the working connection (such as an optical channel data unit label switched path) and then, when a working connection fails, the headend node or tailend node selects a protecting connection for passing data within the mesh network. The set up and activation of the protecting connections may be referred to as restoration or protection.
Dedicated protection mechanisms, where network resources are committed to act as backup for working connections, have been in use for some time. However, existing recovery mechanisms are not adequate to handle switching and reversion when multiple paths and multiple failures are involved for the same service. Systems and methods are needed for multi-level recovery (MLR), and for implementation of such protection, in order to increase network speed, reliability, and resilience.